http://lod.bco-dmo.org/id/dataset/3449
eng; USA
utf8
dataset
Highest level of data collection, from a common set of sensors or instrumentation, usually within the same research project
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
2011-03-11
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Groundfish Trawl Nets Designed to Reduce the Bycatch of Cod: catch data from Fishing Vessels NEC-MP2000-2 in the Gulf of Maine from 2000-2002 (NEC-CoopRes project)
2011-03-30
publication
2011-03-30
revision
BCO-DMO Linked Data URI
2011-03-30
creation
http://lod.bco-dmo.org/id/dataset/3449
Michael Pol
Massachusetts Division of Marine Fisheries
principalInvestigator
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
publisher
Cite this dataset as: Pol, M. (2011) Groundfish Trawl Nets Designed to Reduce the Bycatch of Cod: catch data from Fishing Vessels NEC-MP2000-2 in the Gulf of Maine from 2000-2002 (NEC-CoopRes project). Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 20110330) Version Date 2011-03-30 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/3449 [access date]
Groundfish Trawl Nets Designed to Reduce the Bycatch of Cod: catch data Dataset Description: <p>Testing of two experimental trawl nets established that catch rates of Atlantic cod Gadus morhua could be reduced from standard practices while allowing the targeting of flatfish Pleuronectidae. The Ribas and topless nets both modify the top half of a trawl net; the Ribas net by using large square mesh; the topless net by removing much of the twine in the top of the net. Seventy pairs of alternate tows showed reductions of cod catch rates (kg/hr) that exceeded 76% for both nets. Catch rates of sublegal (&lt;33 cm TL) yellowtail flounder Limanda ferruginea were more than 74% lower for both nets, compared to standard flatfish trawl. Reductions of sublegal (&lt;33 cm) catch rates for winter flounder Pseudopleuronectes americanus exceeded 61%. Significant reductions occurred in legal catch for yellowtail (&gt;32%) and winter flounders (&gt;44%) with some evidence that this reduction was lower for the topless trawl. Underwater video showed cod exiting the nets through the top mesh and through the gap made by the removal of twine.<br />
(from abstract, <a target="_blank" href="http://www.northeastconsortium.org/ProjectFileDownload.pm?report_id=92&amp;table=project_report">final report</a>)</p> Methods and Sampling: <p>The two experimental net designs were tested against a standard design using the paired tow method (Wileman et al. 1996; DeAlteris et al. 1999). Under this protocol, tows were repeated as similarly as possible in pairs, with one tow using an experimental net and the other a standard net. When possible, tow position, tow duration, and tides were duplicated, with one leg of the pair immediately following the other leg.</p>
<p>To allow simultaneous testing on two vessels, two standard nets were constructed of 15.2 cm 3 mm diamond polyethylene (PE) mesh throughout, with 50 mesh diameter 16.5-cm square knotless mesh in the codend, 20 meshes wide on the top and bottom. The headrope and footrope lengths were 12.2 and 18.3 meters (Figure 1). The fishing circle in the standard nets was 140 meshes. The Ribas (Figure 2) and topless (Figure 3) experimental nets were also constructed of 15.2-cm PE mesh with 75 mesh diameter 16.5-cm square mesh in the codend, 25 meshes wide on the top and bottom. The Ribas net replaced 15.2-cm diamond mesh on the top middle of the net with 25 meshes wide of 20.3-cm square mesh from the headrope to the codend. This design had a headrope and footrope length of 18.3 m. The two experimental nets had fishing circles with 100 meshes. All three codends had chaffing gear on the bottom half, consisting of unbraided strands of PE twine.</p>
<p>The topless net has no top wings, allowing the headrope to follow a taper of the net's gore into the top belly, reaching a length of 27.1 m. The bottom half of this net and the Ribas net are identical. Two sweeps were used during this study; a sweep with 15.2 cm cookies and a sweep with 10.2 cm cookies was used to increase flatfish catch rates.</p>
<p>Catch sampling was conducted by trained observers following protocols established by NMFS and modified by DMF for this study. For each tow, position, time, duration, weather conditions, catch composition and weights of all species, and length frequencies of target species were recorded. In cases of large volumes, subsampling of catch and extrapolation were performed using standard DMF protocols.</p>
<p>Underwater video of cod and flatfish behavior was acquired with a third-wire pan-and-tilt system developed by DMF. The camera was mounted on the headrope of the experimental nets. This system allows for viewing of the net while it is being towed. The pan-and-tilt unit has a 360-degree range of motion, allowing an ondeck operator to point the camera in a useful direction. Performance of the modified gear was viewed by the operator during filming and again later by DMF personnel at least once. Cod and flatfish reactions were logged and classified into two basic categories: fish that escaped and fish that are caught in the net. Flatfish species could not be distinguished due to inadequate video resolution and were grouped together.</p>
Funding provided by NorthEast Consortium (NEC) Award Number: unknown NEC-CoopRes NEC
onGoing
Michael Pol
Massachusetts Division of Marine Fisheries
508-990-2860x116
1213 Purchase St., 3rd floor
New Bedford
MA
02740
USA
mike.pol@state.ma.us
pointOfContact
asNeeded
Dataset Version: 20110330
Unknown
catch
depth
gear_type
haul
lat_begin
lat_end
lon_begin
lon_end
name_common
species
tow_duration
valid_tow_flag
weight_lb
day_local
month_local
year
yrday_local
time_begin_local
Beam Trawl
theme
None, User defined
No BCO-DMO term
depth
haul_id
latitude begin
latitude at end time of measurement
longitude begin
longitude at end time of measurement
species scientific name (binomial)
weight
day_local
month_local
year
day of year and decimal time (local time zone)
time_start_local
featureType
BCO-DMO Standard Parameters
Beam Trawl
instrument
BCO-DMO Standard Instruments
NEC-MP2000-2
service
Deployment Activity
Gulf of Maine
place
Locations
otherRestrictions
otherRestrictions
Access Constraints: none. Use Constraints: Please follow guidelines at: http://www.bco-dmo.org/terms-use Distribution liability: Under no circumstances shall BCO-DMO be liable for any direct, incidental, special, consequential, indirect, or punitive damages that result from the use of, or the inability to use, the materials in this data submission. If you are dissatisfied with any materials in this data submission your sole and exclusive remedy is to discontinue use.
NorthEast Consortium
http://northeastconsortium.org/
NorthEast Consortium
The Northeast Consortium encourages and funds
cooperative research and monitoring projects in the Gulf of Maine and Georges Bank that have effective,
equal partnerships among fishermen, scientists, educators, and marine resource managers.
At the 2008 Maine Fisheremen's Forum, the Northeast Consortium organized a session on data collection and availability. Participants included several key organizations in the Gulf of Maine area, sharing what data are out there and how you can find them.
The Northeast Consortium has joined the Gulf of Maine Ocean Data Partnership. The purpose of the GoMODP is to promote and coordinate the sharing, linking, electronic dissemination, and use of data on the Gulf of Maine region.
The Northeast Consortium was created in 1999 to encourage and fund effective, equal partnerships among commercial fishermen, scientists, and other stakeholders to engage in cooperative research and monitoring projects in the Gulf of Maine and Georges Bank. The Northeast Consortium consists of four research institutions (University of New Hampshire, University of Maine, Massachusetts Institute of Technology, and Woods Hole Oceanographic Institution), which are working together to foster this initiative.
The Northeast Consortium administers nearly $5M annually from the National Oceanic and Atmospheric Administration for cooperative research on a broad range of topics including gear selectivity, fish habitat, stock assessments, and socioeconomics. The funding is appropriated to the National Marine Fisheries Service and administered by the University of New Hampshire on behalf of the Northeast Consortium. Funds are distributed through an annual open competition, which is announced via a Request for Proposals (RFP). All projects must involve partnership between commercial fishermen and scientists.
The Northeast Consortium seeks to fund projects that will be conducted in a responsible manner. Cooperative research projects should be designed to minimize any negative impacts to ecosystems or marine organisms, and be consistent with accepted ethical research practices, including the use of animals and human subjects in research, scrutiny of research protocols by an institutional board of review, etc.
NEC
largerWorkCitation
program
Northeast Consortium: Cooperative Research
http://northeastconsortium.org/
Northeast Consortium: Cooperative Research
<p>The Northeast Consortium encourages and funds cooperative research and monitoring projects in the Gulf of Maine and Georges Bank that have effective, equal partnerships among fishermen, scientists, educators, and marine resource managers.</p>
<p>The Northeast Consortium seeks to fund projects that will be conducted in a responsible manner. Cooperative research projects are designed to minimize any negative impacts to ecosystems or marine organisms, and be consistent with accepted ethical research practices, including the use of animals and human subjects in research, scrutiny of research protocols by an institutional board of review, etc.</p>
NEC-CoopRes
largerWorkCitation
project
eng; USA
oceans
Gulf of Maine
2011-03-30
Georges Bank, Gulf of Maine
0
BCO-DMO catalogue of parameters from Groundfish Trawl Nets Designed to Reduce the Bycatch of Cod: catch data from Fishing Vessels NEC-MP2000-2 in the Gulf of Maine from 2000-2002 (NEC-CoopRes project)
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
http://lod.bco-dmo.org/id/dataset-parameter/23896.rdf
Name: catch
Units: kg/hour
Description: <p>adjusted catch per hour</p>
http://lod.bco-dmo.org/id/dataset-parameter/23897.rdf
Name: depth
Units: fathoms
Description: <p>depth at start of tow from echosounder</p>
http://lod.bco-dmo.org/id/dataset-parameter/23898.rdf
Name: gear_type
Units: text
Description: <p>type of gear used; see final report for description</p>
http://lod.bco-dmo.org/id/dataset-parameter/23899.rdf
Name: haul
Units: integer
Description: <p>haul number</p>
http://lod.bco-dmo.org/id/dataset-parameter/23900.rdf
Name: lat_begin
Units: decimal degrees
Description: <p>latitude at start of haul; North is positive</p>
http://lod.bco-dmo.org/id/dataset-parameter/23901.rdf
Name: lat_end
Units: decimal degrees
Description: <p>latitude at end of haul; North is positive</p>
http://lod.bco-dmo.org/id/dataset-parameter/23902.rdf
Name: lon_begin
Units: decimal degrees
Description: <p>longitude at start of haul; East is positive</p>
http://lod.bco-dmo.org/id/dataset-parameter/23903.rdf
Name: lon_end
Units: decimal degrees
Description: <p>longitude at end of haul; East is positive</p>
http://lod.bco-dmo.org/id/dataset-parameter/23904.rdf
Name: name_common
Units: text
Description: <p>common name of fish</p>
http://lod.bco-dmo.org/id/dataset-parameter/23905.rdf
Name: species
Units: text
Description: <p>taxonomic name of this</p>
http://lod.bco-dmo.org/id/dataset-parameter/23906.rdf
Name: tow_duration
Units: hours
Description: <p>duration of tow</p>
http://lod.bco-dmo.org/id/dataset-parameter/23907.rdf
Name: valid_tow_flag
Units: text
Description: <p>true=good tow; false=not good tow</p>
http://lod.bco-dmo.org/id/dataset-parameter/23908.rdf
Name: weight_lb
Units: lb
Description: <p>catch weight round weight in pounds</p>
http://lod.bco-dmo.org/id/dataset-parameter/23909.rdf
Name: day_local
Units: 1 to 31
Description: <p>day of month in local time</p>
http://lod.bco-dmo.org/id/dataset-parameter/23910.rdf
Name: month_local
Units: 1 to 12
Description: <p>month in local time</p>
http://lod.bco-dmo.org/id/dataset-parameter/23911.rdf
Name: year
Units: YYYY
Description: <p>year of sampling</p>
http://lod.bco-dmo.org/id/dataset-parameter/23912.rdf
Name: yrday_local
Units: 1 to 365
Description: <p>local day and decimal time as 326.5 for the 326th day of the year or November 22 at 1200 hours (noon)</p>
http://lod.bco-dmo.org/id/dataset-parameter/24090.rdf
Name: time_begin_local
Units: HHmm
Description: <p>time at start of haul</p>
GB/NERC/BODC > British Oceanographic Data Centre, Natural Environment Research Council, United Kingdom
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
392557
https://datadocs.bco-dmo.org/file/JEE1nomCKgwWEW/cod_redux_catch.csv
cod_redux_catch.csv
Primary data file for dataset ID 3449
download
https://osprey.bco-dmo.org/dataset/3449/data/download
download
onLine
dataset
<p>The two experimental net designs were tested against a standard design using the paired tow method (Wileman et al. 1996; DeAlteris et al. 1999). Under this protocol, tows were repeated as similarly as possible in pairs, with one tow using an experimental net and the other a standard net. When possible, tow position, tow duration, and tides were duplicated, with one leg of the pair immediately following the other leg.</p>
<p>To allow simultaneous testing on two vessels, two standard nets were constructed of 15.2 cm 3 mm diamond polyethylene (PE) mesh throughout, with 50 mesh diameter 16.5-cm square knotless mesh in the codend, 20 meshes wide on the top and bottom. The headrope and footrope lengths were 12.2 and 18.3 meters (Figure 1). The fishing circle in the standard nets was 140 meshes. The Ribas (Figure 2) and topless (Figure 3) experimental nets were also constructed of 15.2-cm PE mesh with 75 mesh diameter 16.5-cm square mesh in the codend, 25 meshes wide on the top and bottom. The Ribas net replaced 15.2-cm diamond mesh on the top middle of the net with 25 meshes wide of 20.3-cm square mesh from the headrope to the codend. This design had a headrope and footrope length of 18.3 m. The two experimental nets had fishing circles with 100 meshes. All three codends had chaffing gear on the bottom half, consisting of unbraided strands of PE twine.</p>
<p>The topless net has no top wings, allowing the headrope to follow a taper of the net's gore into the top belly, reaching a length of 27.1 m. The bottom half of this net and the Ribas net are identical. Two sweeps were used during this study; a sweep with 15.2 cm cookies and a sweep with 10.2 cm cookies was used to increase flatfish catch rates.</p>
<p>Catch sampling was conducted by trained observers following protocols established by NMFS and modified by DMF for this study. For each tow, position, time, duration, weather conditions, catch composition and weights of all species, and length frequencies of target species were recorded. In cases of large volumes, subsampling of catch and extrapolation were performed using standard DMF protocols.</p>
<p>Underwater video of cod and flatfish behavior was acquired with a third-wire pan-and-tilt system developed by DMF. The camera was mounted on the headrope of the experimental nets. This system allows for viewing of the net while it is being towed. The pan-and-tilt unit has a 360-degree range of motion, allowing an ondeck operator to point the camera in a useful direction. Performance of the modified gear was viewed by the operator during filming and again later by DMF personnel at least once. Cod and flatfish reactions were logged and classified into two basic categories: fish that escaped and fish that are caught in the net. Flatfish species could not be distinguished due to inadequate video resolution and were grouped together.</p>
from Cruise: NEC-MP2000-2 <p>multiple vessels</p>
Specified by the Principal Investigator(s)
<p>Catch rates were compared for cod (kept and discard combined), yellowtail flounder Limanda ferruginea (legal and sublegal separately), and winter flounder Pleuronectes americanus (legal and sublegal). Due to non-normal distributions of data, transformations of the logarithm of the rate plus 1 were performed. Transformed rates were then tested first with paired t-tests, and then with ANOVA modified for unequal sample size, with net and boat as factors (Sokal and Rohlf 1995). Tukey's b method was next used to find significant differences in means, if any.</p>
<p>Lengths of cod and commercially valuable flatfish were collected to the extent practicable; often all individuals caught were measured. These lengths were combined across all tows. When subsamples were measured or when kept and discarded fish were measured separately, the total estimated number of individuals (N) at each length was extrapolated from the proportion of the subsample to the total catch. These lengths were compared between experimental and controlled tests using the Kolmogorov-Smirnov tests, adjusted for sample sizes following DeAlteris et al. (1999) (Sprent 1989). Standard fishing practices were followed as much as possible. Fishing locations were selected to optimize catches of cod and flatfish.</p>
Specified by the Principal Investigator(s)
asNeeded
7.x-1.1
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
Beam Trawl
Beam Trawl
PI Supplied Instrument Name: Beam Trawl PI Supplied Instrument Description:Tested two experimental trawl nets, Ribas net and topless net. Instrument Name: Beam Trawl Instrument Short Name:Beam trawl Instrument Description: A beam trawl consists of a cone-shaped body ending in a bag or codend, which retains the catch. In these trawls the horizontal opening of the net is provided by a beam, made of wood or metal, which is up to 12 m long. The vertical opening is provided by two hoop-like trawl shoes mostly made from steel. No hydrodynamic forces are needed to keep a beam trawl open. The beam trawl is normally towed on outriggers, one trawl on each side.
While fishing for flatfish the beam trawl is often equipped with tickler chains to disturb the fish from the seabed. For operations on very rough fishing grounds they can be equipped with chain matrices. Chain matrices are rigged between the beam and the groundrope and prevent boulders/stones from being caught by the trawl. Shrimp beam trawls are not so heavy and have smaller mesh sizes. A bobbin of groundrope with rubber bobbins keeps the shrimp beam trawl in contact with the bottom and gives flatfish the opportunity to escape.
Close bottom contact is necessary for successful operation. To avoid bycatch of most juvenile fishes selectivity devices are assembled (sieve nets, sorting grids, escape holes). While targeting flatfish the beam trawls are towed up to seven knots, therefore the gear is very heavy; the largest gears weighs up to 10 ton. The towing speed for shrimp is between 2.5 and 3 knots.
(from: http://www.fao.org/fishery/geartype/305/en) Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/24/
Cruise: NEC-MP2000-2
NEC-MP2000-2
Fishing Vessels
vessel
NEC-MP2000-2
Michael Pol
Massachusetts Division of Marine Fisheries
http://northeastconsortium.org/ProjectFileDownload.pm?report_id=92&table=project_report
Report describing NEC-MP2000-2
Fishing Vessels
vessel